Generate random string in powershell

random-string-generator.ps1

#lowercase letters/numbers only
-join ((48..57) + (97..122) | Get-Random -Count 32 | % {[char]$_})
# all characters
-join ((33..126) | Get-Random -Count 32 | % {[char]$_})

Keep in mind that the -Maximium is exclusive unlike the array.
so to include 126 do
-join ((1..100) | %{get-random -minimum 33 -maximum 127 | %{[char]$_}})

Using ForEach with a nested call to Get-Random on the input ranges is another way to avoid repeats:

-join (1..20 | ForEach {[char]((97..122) + (48..57) | Get-Random)})

if hex digits are good enough you might consider this
-join ((1..8) | % { "{0:X}" -f ( Get-Random -min 0 -max 256 ) })